Simulated Effects of Soil Temperature and Salinity on Capacitance Sensor Measurements
Dielectric measurement techniques are used widely for estimation of water contentin environmental media. However, factors such as temperature and salinity affecting thereadings require further quantitative investigation and explanation. Theoretical sensitivities ofcapacitance sensors to liquid salin...
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2007-04-01
|
| Series: | Sensors |
| Subjects: | |
| Online Access: | http://www.mdpi.com/1424-8220/7/4/548/ |
| _version_ | 1828357764010737664 |
|---|---|
| author | Timothy R. Green Mike Schwank |
| author_facet | Timothy R. Green Mike Schwank |
| author_sort | Timothy R. Green |
| collection | DOAJ |
| description | Dielectric measurement techniques are used widely for estimation of water contentin environmental media. However, factors such as temperature and salinity affecting thereadings require further quantitative investigation and explanation. Theoretical sensitivities ofcapacitance sensors to liquid salinity and temperature of porous media were derived andcomputed using a revised electrical circuit analogue model in conjunction with a dielectricmixing model and a finite element model of Maxwell’s equation to compute electrical fielddistributions. The mixing model estimates the bulk effective complex permittivities of solid-water-air media. The real part of the permittivity values were used in electric field simulations,from which different components of capacitance were calculated via numerical integration forinput to the electrical circuit analogue. Circuit resistances representing the dielectric losses werecalculated from the complex permittivity of the bulk soil and from the modeled fields. Resonantfrequencies from the circuit analogue were used to update frequency-dependent variables in aniterative manner. Simulated resonant frequencies of the capacitance sensor display sensitivitiesto both temperature and salinity. The gradients in normalized frequency with temperatureranged from negative to positive values as salinity increased from 0 to 10 g L-1. The modeldevelopment and analyses improved our understanding of processes affecting the temperatureand salinity sensitivities of capacitance sensors in general. This study provides a foundation forfurther work on inference of soil water content under field conditions. |
| first_indexed | 2024-04-14T03:20:28Z |
| format | Article |
| id | doaj.art-fed7db04d9a24e5fbdeebd399fa30744 |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-04-14T03:20:28Z |
| publishDate | 2007-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sensors |
| spelling | doaj.art-fed7db04d9a24e5fbdeebd399fa307442022-12-22T02:15:20ZengMDPI AGSensors1424-82202007-04-017454857710.3390/s7040548Simulated Effects of Soil Temperature and Salinity on Capacitance Sensor MeasurementsTimothy R. GreenMike SchwankDielectric measurement techniques are used widely for estimation of water contentin environmental media. However, factors such as temperature and salinity affecting thereadings require further quantitative investigation and explanation. Theoretical sensitivities ofcapacitance sensors to liquid salinity and temperature of porous media were derived andcomputed using a revised electrical circuit analogue model in conjunction with a dielectricmixing model and a finite element model of Maxwell’s equation to compute electrical fielddistributions. The mixing model estimates the bulk effective complex permittivities of solid-water-air media. The real part of the permittivity values were used in electric field simulations,from which different components of capacitance were calculated via numerical integration forinput to the electrical circuit analogue. Circuit resistances representing the dielectric losses werecalculated from the complex permittivity of the bulk soil and from the modeled fields. Resonantfrequencies from the circuit analogue were used to update frequency-dependent variables in aniterative manner. Simulated resonant frequencies of the capacitance sensor display sensitivitiesto both temperature and salinity. The gradients in normalized frequency with temperatureranged from negative to positive values as salinity increased from 0 to 10 g L-1. The modeldevelopment and analyses improved our understanding of processes affecting the temperatureand salinity sensitivities of capacitance sensors in general. This study provides a foundation forfurther work on inference of soil water content under field conditions.http://www.mdpi.com/1424-8220/7/4/548/soil water contentcapacitancepermittivityelectrical conductivityresonant frequency. |
| spellingShingle | Timothy R. Green Mike Schwank Simulated Effects of Soil Temperature and Salinity on Capacitance Sensor Measurements Sensors soil water content capacitance permittivity electrical conductivity resonant frequency. |
| title | Simulated Effects of Soil Temperature and Salinity on Capacitance Sensor Measurements |
| title_full | Simulated Effects of Soil Temperature and Salinity on Capacitance Sensor Measurements |
| title_fullStr | Simulated Effects of Soil Temperature and Salinity on Capacitance Sensor Measurements |
| title_full_unstemmed | Simulated Effects of Soil Temperature and Salinity on Capacitance Sensor Measurements |
| title_short | Simulated Effects of Soil Temperature and Salinity on Capacitance Sensor Measurements |
| title_sort | simulated effects of soil temperature and salinity on capacitance sensor measurements |
| topic | soil water content capacitance permittivity electrical conductivity resonant frequency. |
| url | http://www.mdpi.com/1424-8220/7/4/548/ |
| work_keys_str_mv | AT timothyrgreen simulatedeffectsofsoiltemperatureandsalinityoncapacitancesensormeasurements AT mikeschwank simulatedeffectsofsoiltemperatureandsalinityoncapacitancesensormeasurements |